Urea substituted imidazoquinoline ethers

ABSTRACT

Imidazoquinoline and tetrahydroimidazoquinoline compounds that contain ether and urea functionality at the I-position are useful as immune response modifiers. The compounds and compositions of the invention can induce the biosynthesis of various cytokines and are useful in the treatment of a variety of conditions including viral diseases and neoplastic diseases.

This application claims the benefit of previously filed ProvisionalApplication Ser. No. 60/254,218, filed Dec. 8, 2000.

FIELD OF THE INVENTION

This invention relates to imidazoquinoline compounds that have ether andurea functionality at the 1-position, and to pharmaceutical compositionscontaining such compounds. A further aspect of this invention relates tothe use of these compounds as immunomodulators, for inducing cytokinebiosynthesis in animals, and in the treatment of diseases, includingviral and neoplastic diseases.

BACKGROUND OF THE INVENTION

The first reliable report on the 1H-imidazo[4,5-c]quinoline ring system,Backman et al., J. Org. Chem. 15, 1278-1284 (1950) describes thesynthesis of1-(6-methoxy-8-quinolinyl)-2-methyl-1H-imidazo[4,5-c]quinoline forpossible use as an antimalarial agent. Subsequently, syntheses ofvarious substituted 1H-imidazo[4,5-c]quinolines were reported. Forexample, Jain et al., J. Med. Chem. 11, pp. 87-92 (1968), synthesizedthe compound 1-[2-(4-piperidyl)ethyl]-1H-imidazo[4,5-c]quinoline as apossible anticonvulsant and cardiovascular agent. Also, Baranov et al.,Chem. Abs. 85, 94362 (1976), have reported several2-oxoimidazo[4,5-c]quinolines, and Berenyi et al., J. Heterocyclic Chem.18, 1537-1540 (1981), have reported certain2-oxoimidazo[4,5-c]quinolines.

Certain 1H-imidazo[4,5-c]quinolin-4-amines and 1- and 2-substitutedderivatives thereof were later found to be useful as antiviral agents,bronchodilators and immunomodulators. These are described in, interalia, U.S. Pat. Nos. 4,689,338; 4,698,348; 4,929,624; 5,037,986;5,268,376; 5,346,905; and 5,389,640, all of which are incorporatedherein by reference.

There continues to be interest in the imidazoquinoline ring system.

Certain 1H-imidazo[4,5-c]naphthyridine-4-amines, 1H-imidazo[4,5-c]pyridin-4-amines, and 1H-imidazo[4,5-c]quinolin-4-amines havingan ether containing substituent at the 1 position are known. These aredescribed in U.S. Pat. Nos. 5,268,376; 5,389,640; 5,494,916; and WO99/29693.

Despite these attempts to identify compounds that are useful as immuneresponse modifiers, there is a continuing need for compounds that havethe ability to modulate the immune response, by induction of cytokinebiosynthesis or other mechanisms.

SUMMARY OF THE INVENTION

We have found a new class of compounds that are useful in inducingcytokine biosynthesis in animals. Accordingly, this invention providesimidazoquinoline-4-amine and tetrahydroimidazoquinoline-4-aminecompounds that have an ether and urea containing substituent at the1-position. The compounds are defined by Formulas (I) and (II), whichare defined in more detail infra. These compounds share the generalstructural formula:

wherein X, R₁, R₂, and R are as defined herein for each class ofcompounds having Formulas (I) and (II).

The compounds of Formulas (I) and (II) are useful as immune responsemodifiers due to their ability to induce cytokine biosynthesis andotherwise modulate the immune response when administered to animals.This makes the compounds useful in the treatment of a variety ofconditions such as viral diseases and tumors that are responsive to suchchanges in the immune response.

The invention further provides pharmaceutical compositions containingthe immune response modifying compounds, and methods of inducingcytokine biosynthesis in an animal, treating a viral infection in ananimal, and/or treating a neoplastic disease in an animal byadministering a compound of Formula (I) or (II) to the animal.

In addition, the invention provides methods of synthesizing thecompounds of the invention and novel intermediates useful in thesynthesis of these compounds.

DETAILED DESCRIPTION OF THE INVENTION

As mentioned earlier, we have found certain compounds that inducecytokine biosynthesis and modify the immune response in animals. Suchcompounds are represented by Formulas (I) and (II), as shown below.

Imidazoquinoline compounds of the invention, which have ether and ureafunctionality at the 1-position are represented by Formula (I):

wherein:

X is —CHR₅—, —CHR₅-alkyl-, or —CHR₅-alkenyl-;

-   -   R₁ is selected from the group consisting of:        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heteroaryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heterocyclyl;        -   —R₄—NR₈—CR₃—NR₅R₇;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heteroaryl; and        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heterocyclyl;    -   R₂ is selected from the group consisting of:        -   -hydrogen;        -   -alkyl;        -   -alkenyl;        -   -aryl;        -   -heteroaryl;        -   -heterocyclyl;        -   -alkyl-Y-alkyl;        -   -alkyl-Y-alkenyl;        -   -alkyl-Y-aryl; and        -   - alkyl or alkenyl substituted by one or more substituents            selected from the group consisting of:            -   —OH;            -   -halogen;            -   —CO—N(R₅)₂;            -   —CO—C₁₋₁₀ alkyl;            -   —CO—O—C₁₋₁₀ alkyl;            -   —N₃;            -   -aryl;            -   -heteroaryl;            -   -heterocyclyl;            -   —CO-aryl; and            -   —CO-heteroaryl;    -   each R₃ is ═O or ═S;    -   each R₄ is independently alkyl or alkenyl, which may be        interrupted by one or more —O— groups;    -   each R₅ is independently H or C₁₋₁₀ alkyl;    -   R₆ is a bond, alkyl, or alkenyl, which may be interrupted by one        or more —O— groups;    -   R₇ is H or C₁₋₁₀ alkyl which may be interrupted by a hetero        atom, or R₇ can join with R₅ to form a ring;    -   R₈ is H, C₁₋₁₀ alkyl, or arylalkyl; or R₄ and R₈ can join        together to form a ring;    -   R₉ is C₁₋₁₀ alkyl which can join with R₈ to form a ring;    -   each Y is independently —O— or —S(O)₀₋₂—;    -   Z is a bond, —CO—, or —SO₂—;    -   n is 0 to 4; and    -   each R present is independently selected from the group        consisting of C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, hydroxy, halogen and        trifluoromethyl;    -   or a pharmaceutically acceptable salt thereof.

The invention also includes tetrahydroimidazoquinoline compounds thatbear an ether and urea containing substituent at the 1-position. Suchtetrahydroimidazoquinoline compounds are represented by Formula (II):

wherein:

-   -   X is —CHR₅—, —CHR₅-alkyl-, or —CHR₅-alkenyl-;    -   R₁ is selected from the group consisting of:        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heteroaryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heterocyclyl;        -   —R₄—NR₈—CR₃—NR₅R₇;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-alkyl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heteroaryl; and        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heterocyclyl;    -   R₂ is selected from the group consisting of:        -   -hydrogen;        -   -alkyl;        -   -alkenyl;        -   -aryl;        -   -heteroaryl;        -   -heterocyclyl;        -   -alkyl-Y-alkyl;        -   -alkyl-Y-alkenyl;        -   -alkyl-Y-aryl; and        -   -alkyl or alkenyl substituted by one or more substituents            selected from the group consisting of:            -   —OH;            -   -halogen;            -   —N(R₅)₂;            -   —CO—N(R₅)₂;            -   —CO—C₁₋₁₀ alkyl;            -   —CO—O—C₁₋₁₀ alkyl;            -   —N₃;            -   -aryl;            -   -heteroaryl;            -   -heterocyclyl;            -   —CO-aryl; and            -   —CO-heteroaryl;    -   each R₃ is ═O or ═S;    -   each R₄ is independently alkyl or alkenyl, which may be        interrupted by one or more —O— groups;    -   each R₅ is independently H or C₁₋₁₀ alkyl;    -   R₆ is a bond, alkyl, or alkenyl, which may be interrupted by one        or more groups;    -   R₇ is H or C₁₋₁₀ alkyl which may be interrupted by a hetero        atom, or R₇ can join with R₅ to form a ring;    -   R₈ is H, C₁₋₁₀ alkyl, or arylalkyl; or R₄ and R₈ can join        together to form a ring;    -   R₉ is C₁₋₁₀ alkyl which can join together with R₈ to form a        ring;    -   each Y is independently —O— or —S(O)₀₋₂—;    -   Z is a bond, —CO—, or —SO₂—;    -   n is 0 to 4; and    -   each R present is independently selected from the group        consisting of C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, hydroxy, halogen, and        trifluoromethyl;        or a pharmaceutically acceptable salt thereof.        Preparation of the Compounds

Compounds of the invention can be prepared according to Reaction SchemeI where R, R₂, R₃, R₄, R₅, R₈, X and n are as defined above, BOC istert-butoxycarbonyl and R₁₁ is -Z-R₆-alkyl, -Z-R₆-alkenyl, -Z-R₆-aryl,-Z-R₆-heteroaryl, -Z-R₆-heterocyclyl or R₁₁ is R₇ where R₆, R₇ and Z areas defined above.

In step (1) of Reaction Scheme I the amino group of an aminoalcohol ofFormula X is protected with a tert-butoxycarbonyl group. A solution ofthe aminoalcohol in tetrahydrofuran is treated with di-tert-butyldicarbonate in the presence of a base such as sodium hydroxide. Manyaminoalcohols of Formula X are commercially available; others can beprepared using known synthetic methods.

In step (2) of Reaction Scheme I a protected aminoalcohol of Formula XIis converted to an iodide of Formula XII. Iodine is added to a solutionof triphenylphosphine and imidazole in dichloromethane; then a solutionof a protected aminoalcohol of Formula XI in dichloromethane is added.The reaction is carried out at ambient temperature.

In step (3) of Reaction Scheme I a 1H-imidazo[4,5-c]quinolin-1-ylalcohol of Formula XIII is alkylated with an iodide of Formula XII toprovide a 1H-imidazo[4,5-c]quinolin-1-yl ether of Formula XIV. Thealcohol of Formula XIII is reacted with sodium hydride in a suitablesolvent such as N,N-dimethylformamide to form an alkoxide. The iodide isadded to the alkoxide solution at ambient temperature. After theaddition is complete the reaction is stirred at an elevated temperature(˜100° C.). Many compounds of Formula XIII are known, see for example,Gerster, U.S. Pat. No. 4,689,338; others can readily be prepared usingknown synthetic routes, see for example, Gerster et al., U.S. Pat. No.5,605,899 and Gerster, U.S. Pat. No. 5,175,296.

In step (4) of Reaction Scheme I a 1H-imidazo[4,5-c]quinolin-1-yl etherof Formula XIV is oxidized to provide a1H-imidazo[4,5-c]quinoline-5N-oxide of Formula XV using a conventionaloxidizing agent capable of forming N-oxides. Preferably a solution of acompound of Formula XIV in chloroform is oxidized using3-chloroperoxybenzoic acid at ambient temperature.

In step (5) of Reaction Scheme I a 1H-imidazo[4,5-c]quinoline-5N-oxideof Formula XV is aminated to provide a 1H-imidazo[4,5-c]quinolin-4-amineof Formula XVI. Step (5) involves (i) reacting a compound of Formula XVwith an acylating agent and then (ii) reacting the product with anaminating agent. Part (i) of step (5) involves reacting an N-oxide ofFormula XV with an acylating agent Suitable acylating agents includealkyl- or arylsulfonyl chlorides (e.g., benezenesulfonyl chloride,methanesulfonyl chloride, p-toluenesulfonyl chloride). Arylsulfonylchlorides are preferred. Paratoluenesulfonyl chloride is most preferred.Part (ii) of step (5) involves reacting the product of part (i) with anexcess of an aminating agent. Suitable aminating agents include ammonia(e.g., in the form of ammonium hydroxide) and ammonium salts (e.g.,ammonium carbonate, ammonium bicarbonate, ammonium phosphate). Ammoniumhydroxide is preferred. The reaction is preferably carried out bydissolving the N-oxide of Formula XV in an inert solvent such asdichloromethane or 1,2-dichloroethane with heating if necessary, addingthe aminating agent to the solution, and then slowly adding theacylating agent. Optionally the reaction can be carried out in a sealedpressure vessel at an elevated temperature (85-100°).

In step (6) of Reaction Scheme I the protecting group is removed byhydrolysis under acidic conditions to provide a1H-imidazo[4,5-c]quinolin-4-amine of Formula XVII. Preferably thecompound of Formula XVI is treated with hydrochloric acid/ethanol atambient temperature or with gentle heating.

In step (7) of Reaction Scheme I a 1H-imidazo[4,5-c]quinolin-4-amine ofFormula XVII is converted to a urea or thiourea of Formula XVIII usingconventional synthetic methods. For example, a compound of Formula XVIIcan be reacted with an isocyanate of formula R₁₂-N═C═O where R₁₂ is—R₆-alkyl, —R₆-alkenyl, —R₆-aryl, —R₆-heteroaryl or —R₆-heterocyclyl.The reaction can be carried out by adding a solution of the isocyanatein a suitable solvent such as dichloromethane or1-methyl-2-pyrrolidinone to a solution of a compound of Formula XVII atambient temperature. Alternatively, a compound of Formula XVII can bereacted with a thioisocyanate of formula R₁₂—N═C═S, an acyl isocyanateof formula R₁₂—C(O)—N═C═O, a sulfonyl isocyanate of formula—R₁₂—S(O₂)—N═C═O or a carbamoyl chloride of formula R₁₃—N—C(O)Cl whereR₁₃ is R₁₂ or R₇. The product or a pharmaceutically acceptable saltthereof can be isolated using conventional methods.

Compounds of the invention can be prepared according to Reaction SchemeII where R, R₂, R₃, R₄, R₅, R₈, R₁₁, X and n are as defined above andBOC is tert-butoxycarbonyl.

In step (1) of Reaction Scheme II the amino group of an aminoalcohol ofFormula XIX is protected with a tert-butoxycarbonyl group. A solution ofthe aminoalcohol in tetrahydrofuran is treated with di-tert-butyldicarbonate in the presence of a base such as sodium hydroxide. Manyaminoalcohols of Formula XIX are commercially available; others can beprepared using known synthetic methods.

In step (2) of Reaction Scheme II a protected amino alcohol of FormulaXX is converted to a methanesulfonate of Formula XXI. A solution of acompound of Formula XX in a suitable solvent such as dichloromethane istreated with methanesulfonyl chloride in the presence of a base such astriethylamine. The reaction can be carried out at a reduced temperature(0° C.).

In step (3a) of Reaction Scheme II a methanesulfonate of Formula XXI isconverted to an azide of Formula XXII. Sodium azide is added to asolution of a compound of Formula XXI in a suitable solvent such asN,N-dimethylformamide. The reaction can be carried out at an elevatedtemperature (80-100° C.).

In step (3b) of Reaction Scheme II a compound of Formula XXII isalkylated with a halide of formula Hal-R₈ to provide a compound ofFormula XXIII. In compounds where R₈ is hydrogen this step is omitted.The compound of Formula XXII is reacted with sodium hydride in asuitable solvent such as N,N-dimethylformamide or tetrahydrofuran toform the anion and then combined with the halide. The reaction can becarried out at ambient temperature.

In step (4) of Reaction Scheme II an azide of Formula XXII or XXIII isreduced to provide an amine of Formula XXIV. Preferably, the reductionis carried out using a conventional heterogeneous hydrogenation catalystsuch as palladium on carbon. The reaction can conveniently be carriedout on a Parr apparatus in a suitable solvent such as methanol orisopropanol.

In step (5) of Reaction Scheme II a 4-chloro-3-nitroquinoline of FormulaXXV is reacted with an amine of Formula XXIV to provide a3-nitroquinoline of Formula XXVI. The reaction can be carried out byadding an amine of Formula XXIV to a solution of a compound of FormulaXXV in a suitable solvent such as dichloromethane in the presence of abase such as triethylamine. Many quinolines of Formula XXV are knowncompounds or can be prepared using known synthetic methods, see forexample, Gerster, U.S. Pat. No. 4,689,338 and references cited therein.

In step (6) of Reaction Scheme II a 3-nitroquinoline of Formula XXVI isreduced to provide a 3-aminoquinoline of Formula XXVII. Preferably, thereduction is carried out using a conventional heterogeneoushydrogenation catalyst such as platinum on carbon. The reaction canconveniently be carried out on a Parr apparatus in a suitable solventsuch as toluene.

In step (7) of Reaction Scheme II a compound of Formula XXVII is reactedwith a carboxylic acid or an equivalent thereof to provide a1H-imidazo[4,5-c]quinoline of Formula XIV. Suitable equivalents tocarboxylic acid include orthoesters, and 1,1-dialkoxyalkyl alkanoates.The carboxylic acid or equivalent is selected such that it will providethe desired R₂ substituent in a compound of Formula XIV. For example,triethyl orthoformate will provide a compound where R₂ is hydrogen andtriethyl orthovalerate will provide a compound where R₂ is butyl. Thereaction can be run in the absence of solvent or in an inert solventsuch as toluene. The reaction is run with sufficient heating to driveoff any alcohol or water formed as a byproduct of the reaction.Optionally a catalytic amount of pyridine hydrochloride can be included.

Alternatively, step (7) can be carried out by (i) reacting a compound ofFormula XXVII with an acyl halide of formula R₂C(O)Cl and then (ii)cyclizing. In part (i) the acyl halide is added to a solution of acompound of Formula XXVII in an inert solvent such as acetonitrile ordichloromethane. The reaction can be carried out at ambient temperatureor at a reduced temperature. In part (ii) the product of part (i) isheated in an alcoholic solvent in the presence of a base. Preferably theproduct of part (i) is refluxed in ethanol in the presence of an excessof triethylamine or heated with methanolic ammonia.

Steps (8), (9), (10) and (11) are carried out in the same manner assteps (4), (5), (6) and (7) of Reaction Scheme I.

Compounds of the invention can be prepared according to Reaction SchemeIII where R, R₂, R₃, R₄, R₅, R₈, R₁₁, X and n are as defined above.

In step (1) of Reaction Scheme III a 1H-imidazo[4,5-c]quinolin-4-amineof Formula XVII is reduced to provide a6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XXVIII.Preferably the reduction is carried out by suspending or dissolving acompound of Formula XVII in trifluoroacetic acid, adding a catalyticamount of platinum (IV) oxide, and then hydrogenating. The reaction canbe conveniently carried out in a Parr apparatus.

Step (2) is carried out in the same manner as step (7) of ReactionScheme I to provide a6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine of Formula XXIX.The product or a pharmaceutically acceptable salt thereof can beisolated using conventional methods.

Compounds of the invention can also be prepared according to ReactionScheme IV where R, R₁, R₂, X and n are as defined above.

In step (1) of Reaction Scheme IV a 4-chloro-3-nitroquinoline of FormulaXXV is reacted with an amine of formula R₁—O—X—NH₂ to provide a3-nitroquinolin-4-amine of Formula XXX. The reaction can be carried outby adding the amine to a solution of a compound of Formula XXV in asuitable solvent such as chloroform or dichloromethane and optionallyheating. Many quinolines of Formula XXV are known compounds, see forexample, Gerster, U.S. Pat. No. 4,689,338 and references cited therein.

In step (2) of Reaction Scheme IV a 3-nitroquinolin-4-amine of FormulaXXX is reduced using the method of step (6) of Reaction Scheme II toprovide a quinoline-3,4-diamine of Formula XXXI.

In step (3) of Reaction Scheme IV a quinoline-3,4-diamine of FormulaXXXI is cyclized using the method of step (7) of Reaction Scheme II toprovide a 1H-imidazo[4,5-c]quinoline of Formula XXXII.

In step (4) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinoline ofFormula XXXII is oxidized using the method of step (4) of ReactionScheme I to provide a 1H-imidazo[4,5-c]quinoline-5N-oxide of FormulaXXXIII.

In step (5) of Reaction Scheme IV a 1H-imidazo[4,5-c]quinoline-5N-oxideof Formula XXXIII is aminated using the method of step (5) of ReactionScheme I to provide a 1H-imidazo[4,5-c]quinolin-4-amine of Formula I.The product or a pharmaceutically acceptable salt thereof can beisolated using conventional methods.

Compounds of the invention can be prepared according to Reaction SchemeV where R, R₂, R₃, R₄, R₅, R₈, R₁₁, X and n are as defined above.

In step (1) of Reaction Scheme V the BOC group is removed from acompound of Formula XIV using the method of step (6) of Reaction SchemeI to provide a 1H-imidazo[4,5-c]quinoline of Formula XXXIV.

In step (2) of Reaction Scheme V a 1H-imidazo[4,5-c]quinoline of FormulaXXXIV is converted to a urea or thiourea of Formula XXXV using themethod of step (7) of Reaction Scheme I.

In step (3) of Reaction Scheme V a 1H-imidazo[4,5-c]quinoline of FormulaXXXV is oxidized using the method of step (4) of Reaction Scheme I toprovide a 1H-imidazo[4,5-c]quinolin-5N-oxide of Formula XXXVI.

In step (4) of Reaction Scheme V a 1H-imidazo[4,5-c]quinolin-5N-oxide ofFormula XXXVI is aminated using the method of step (5) of ReactionScheme I to provide a 1H-imidazo[4,5-c]quinolin-4-amine of FormulaXVIII. The product or a pharmaceutically acceptable salt thereof can beisolated using conventional methods.

The invention also provides novel compounds useful as intermediates inthe synthesis of the compounds of Formulas (I) and (II). Theseintermediate compounds have the structural Formulas (III) and (IV),described in more detail below.

One class of intermediate compounds has formula (III):

wherein:

-   -   X is —CHR₅—, —CHR₅-alkyl-, or —CHR₅-alkenyl-;    -   R₁ is selected from the group consisting of:        -   —R₄-NR₈—CR₃—NR₅-Z-R₆-alkyl;        -   —R₄-NR₈—CR₃—NR₅-Z-R₆-alkenyl;        -   —R₄-NR₈—CR₃—NR₅-Z-R₆-aryl;        -   —R₄-NR₈—CR₃—NR₅-Z-R₆-heteroaryl;        -   —R₄-NR₈—CR₃—NR₅-Z-R₆-heterocyclyl; and        -   —R₄-NR₈—CR₃—NR₅R₇;        -   —R₄-NR₈—CR₃—NR₉-Z-R₆-alkyl;        -   —R₄-NR₈—CR₃—NR₉-Z-R₆-alkenyl;        -   —R₄-NR₈—CR₃—NR₉-Z-R₆-aryl;        -   —R₄-NR₈—CR₃—NR₉-Z-R₆-heteroaryl; and        -   —R₄-NR₈—CR₃—NR₉-Z-R₆-heterocyclyl;    -   R₂ is selected from the group consisting of:        -   -hydrogen;        -   -alkyl;        -   -alkenyl;        -   -aryl;        -   -heteroaryl;        -   -heterocyclyl;        -   -alkyl-Y-alkyl;        -   -alkyl-Y-alkenyl;        -   -alkyl-Y-aryl; and        -   -alkyl or alkenyl substituted by one or more substituents            selected from the group consisting of:            -   —OH;            -   -halogen;            -   —N(R₅)₂;            -   —CO—N(R₅)₂;            -   —CO—C₁₋₁₀ alkyl;            -   —CO—O—C₁₋₁₀ alkyl;            -   —N₃;            -   -aryl;            -   -heteroaryl;            -   -heterocyclyl;            -   —CO-aryl; and            -   -CO-heteroaryl;    -   each R₃ is ═O or ═S;    -   each R₄ is independently alkyl or alkenyl, which may be        interrupted by one or more —O— groups;    -   each R₅ is independently H or C₁₋₁₀ alkyl;    -   R₆ is a bond, or is alkyl, or alkenyl, which may be interrupted        by one or more —O— groups;    -   R₇ is H or C₁₋₁₀ alkyl which may be interrupted by a hetero        atom, or R₇ can join with R₅ to form a ring;    -   R₈ is H, C₁₋₁₀ alkyl, or arylalkyl; or R₄ and R₈ can join to        form a ring;    -   R₉ is C₁₋₁₀ alkyl which can join together with R₈ to form a        ring;    -   each Y is independently —O— or —S(O)₀₋₂—;    -   Z is a bond, —CO—, or —SO₂—;    -   n is 0 to 4; and    -   each R present is independently selected from the group        consisting of C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, hydroxy, halogen and        trifluoromethyl;    -   or a pharmaceutically acceptable salt thereof.

Another class of intermediate compounds are the imidazoquinoline-N-oxidecompounds of Formula (IV):

wherein

-   -   X is —CHR₅—, —CHR₅-alkylene-, or —CHR₅-alkenylene-;    -   R₁ is selected from the group consisting of:        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heteroaryl;        -   —R₄—NR₈—CR₃—NR₅-Z-R₆-heterocyclyl;        -   —R₄—NR₈—CR₃—NR₅R₇;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-alkyl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-alkenyl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-aryl;        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heteroaryl; and        -   —R₄—NR₈—CR₃—NR₉-Z-R₆-heterocyclyl;    -   each Y is independently —O— or —S(O)₀₋₂—;    -   Z is a bond, —CO— or —SO₂—;    -   each R₄ is independently alkyl or alkenyl, which may be        interrupted by one or more —O— groups;    -   each R₅ is independently H or C₁₋₁₀ alkyl;    -   R₆ is a bond, or is alkyl, or alkenyl, which may be interrupted        by one or more —O— groups;    -   R₇ is H or C₁₋₁₀ alkyl which may be interrupted by a hetero        atom, or R₇ can join with R₅ to form a ring;    -   R₈ is H, C₁₋₁₀ alkyl, or arylalkyl; or R₄ and R₈ can join to        form a ring;    -   R₉ is C₁₋₁₀ alkyl which can join together with R₈ to form a        ring;    -   n is 0 to 4; and    -   each R present is independently selected from the group        consisting of C₁₋₁₀ alkyl, C₁₋₁₀ alkoxy, halogen and        trifluoromethyl;    -   or a pharmaceutically acceptable salt hereof.

As used herein, the terms “alkyl”, “alkenyl” and the prefix “alk-” areinclusive of both straight chain and branched chain groups and of cyclicgroups, i.e. cycloalkyl and cycloalkenyl. Unless otherwise specified,these groups contain from 1 to 20 carbon atoms, with alkenyl groupscontaining from 2 to 20 carbon atoms. Preferred groups have a total ofup to 10 carbon atoms. Cyclic groups can be monocyclic or polycyclic andpreferably have from 3 to 10 ring carbon atoms. Exemplary cyclic groupsinclude cyclopropyl, cyclopropylmethyl, cyclopentyl, cyclohexyl andadamantyl.

In addition, the alkyl and alkenyl portions of —X— groups can beunsubstituted or substituted by one or more substituents, whichsubstituents are selected from the groups consisting of alkyl, alkenyl,aryl, heteroaryl, heterocyclyl, arylalkyl, heteroarylalkyl, andheterocyclylalkyl.

The term “haloallyl” is inclusive of groups that are substituted by oneor more halogen atoms, including perfluorinated groups. This is alsotrue of groups that include the prefix “halo-”. Examples of suitablehaloalkyl groups are chloromethyl, trifluoromethyl, and the like.

The term “aryl” as used herein includes carbocyclic aromatic rings orring systems. Examples of aryl groups include phenyl, naphthyl,biphenyl, fluorenyl and indenyl. The term “heteroaryl” includes aromaticrings or ring systems that contain at least one ring hetero atom (e.g.,O, S, N). Suitable heteroaryl groups include furyl, thienyl, pyridyl,quinolinyl, isoquinolinyl, indolyl, isoindolyl, triazolyl, pyrrolyl,tetrazolyl, imidazolyl, pyrazolyl, oxazolyl, thiazolyl, benzofuranyl,benzothiophenyl, carbazolyl, benzoxazolyl, pyrimidinyl, benzimidazolyl,quinoxalinyl, benzothiazolyl, naphthyridinyl, isoxazolyl, isothiazolyl,purinyl, quinazolinyl, and so on.

“Heterocyclyl” includes non-aromatic rings or ring systems that containat least one ring hetero atom (e.g., O, S, N) and includes all of thefully saturated and partially unsaturated derivatives of the abovementioned heteroaryl groups. Exemplary heterocyclic groups includepyrrolidinyl, tetrahydrofuranyl, morpholinyl, thiomorpholinyl,piperidinyl, piperazinyl, thiazolidinyl, imidazolidinyl,isothiazolidinyl, and the like.

The aryl, heteroaryl, and heterocyclyl groups can be unsubstituted orsubstituted by one or more substituents independently selected from thegroup consisting of alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy,haloalkylthio, halogen, nitro, hydroxy, mercapto, cyano, carboxy,formyl, aryl, aryloxy, arylthio, arylalkoxy, arylalkylthio, heteroaryl,heteroaryloxy, heteroarylthio, heteroarylalkoxy, heteroarylalkylthio,amino, alkylamino, dialkylamino, heterocyclyl, heterocycloalkyl,alkylcarbonyl, alkenylcarbonyl, alkoxycarbonyl, haloalkylcarbonyl,haloalkoxycarbonyl, alkylthiocarbonyl, arylcarbonyl, heteroarylcarbonyl,aryloxycarbonyl, heteroaryloxycarbonyl, arylthiocarbonyl,heteroarylthiocarbonyl, alkanoyloxy, alkanoylthio, alkanoylamino,arylcarbonyloxy, arylcarbonylthio, alkylaminosulfonyl, alkylsulfonyl,arylsulfonyl, heteroarylsulfonyl, aryldiazinyl, alkylsulfonylamino,arylsulfonylamino, arylalkylsulfonylamino, alkylcarbonylamino,alkenylcarbonylamino, arylcarbonylamino, arylalkylcarbonylamino,heteroarylcarbonylamino, heteroarylalkycarbonylamino,alkylsulfonylamino, alkenylsulfonylamino, arylsulfonylamino,arylalkylsulfonylamino, heteroarylsulfonylamino,heteroarylalkylsulfonylamino, alkylaminocarbonylamino,alkenylaminocarbonylamino, arylaminocarbonylamino,arylalkylaminocarbonylamino, heteroarylaminocarbonylamino,heteroarylalkylaminocarbonylamino and, in the case of heterocyclyl, oxo.If any other groups are identified as being “substituted” or “optionallysubstituted”, then those groups can also be substituted by one or moreof the above enumerated substituents.

Certain substituents are generally preferred. For example, preferred R₁groups include —R₄—NR₈—CR₃—NR₅-Z-R₆-alkyl and —R₄—NR₈—CR₃—NR₅-Z-R₆-aryl,wherein the alkyl and aryl groups can be unsubstituted or substituted;and R₄ is preferably ethylene or n-butylene or R₄ and R₈ join to form aring. Preferably no R substituents are present (i.e., n is 0). PreferredR₂ groups include hydrogen, alkyl groups having 1 to 4 carbon atoms(i.e., methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl,and cyclopropylmethyl), methoxyethyl and ethoxymethyl. For substitutedgroups such as substituted alkyl or substituted aryl groups, preferredsubstituents include halogen, nitrile, methoxy, methylthio,trifluoromethyl, and trifluoromethoxy. One or more of these preferredsubstituents, if present, can be present in the compounds of theinvention in any combination.

The invention is inclusive of the compounds described herein in any oftheir pharmaceutically acceptable forms, including isomers (e.g.,diastereomers and enantiomers), salts, solvates, polymorphs, and thelike. In particular, if a compound is optically active, the inventionspecifically includes each of the compound's enantiomers as well asracemic mixtures of the enantiomers.

Pharmaceutical Compositions and Biological Activity

Pharmaceutical compositions of the invention contain a therapeuticallyeffective amount of a compound of the invention as described above incombination with a pharmaceutically acceptable carrier.

The term “a therapeutically effective amount” means an amount of thecompound sufficient to induce a therapeutic effect, such as cytokineinduction, antitumor activity, and/or antiviral activity. Although theexact amount of active compound used in a pharmaceutical composition ofthe invention will vary according to factors known to those of skill inthe art, such as the physical and chemical nature of the compound, thenature of the carrier, and the intended dosing regimen, it isanticipated that the compositions of the invention will containsufficient active ingredient to provide a dose of about 100 ng/kg toabout 50 mg/kg, preferably about 10 μg/kg to about 5 mg/kg, of thecompound to the subject. Any of the conventional dosage forms may beused, such as tablets, lozenges, parenteral formulations, syrups,creams, ointments, aerosol formulations, transdermal patches,transmucosal patches and the like.

The compounds of the invention can be administered as the singletherapeutic agent in the treatment regimen, or the compounds of theinvention may be administered in combination with one another or withother active agents, including additional immune response modifiers,antivirals, antibiotics, etc.

The compounds of the invention have been shown to induce the productionof certain cytokines in experiments performed according to the tests setforth below. These results indicate that the compounds are useful asimmune response modifiers that can modulate the immune response in anumber of different ways, rendering them useful in the treatment of avariety of disorders.

Cytokines whose production may be induced by the administration ofcompounds according to the invention generally include interferon-α(IFN-α) and/or tumor necrosis factor-α (TNF-α) as well as certaininterleukins (IL). Cytokines whose biosynthesis may be induced bycompounds of the invention include IFN-α, TNF-α, IL-1, IL-6, IL-10 andIL-12, and a variety of other cytokines. Among other effects, these andother cytokines can inhibit virus production and tumor cell growth,making the compounds useful in the treatment of viral diseases andtumors. Accordingly, the invention provides a method of inducingcytokine biosynthesis in an animal comprising administering an effectiveamount of a compound or composition of the invention to the animal.

Certain compounds of the invention have been found to preferentiallyinduce the expression of IFN-α in a population of hematopoietic cellssuch as PBMCs (peripheral blood mononuclear cells) containing pDC2 cells(precursor dendritic cell-type 2) without concomitant production ofsignificant levels of inflammatory cytokines.

In addition to the ability to induce the production of cytokines, thecompounds of the invention affect other aspects of the innate immuneresponse. For example, natural killer cell activity may be stimulated,an effect that may be due to cytokine induction. The compounds may alsoactivate macrophages, which in turn stimulates secretion of nitric oxideand the production of additional cytokines. Further, the compounds maycause proliferation and differentiation of B-lymphocytes.

Compounds of the invention also have an effect on the acquired immuneresponse. For example, although there is not believed to be any directeffect on T cells or direct induction of T cell cytokines, theproduction of the T helper type 1 (Th1) cytokine IFN-γ is inducedindirectly and the production of the T helper type 2 (Th2) cytokinesIL4, IL-5 and IL-13 are inhibited upon administration of the compounds.This activity means that the compounds are useful in the treatment ofdiseases where upregulation of the Th1 response and/or downregulation ofthe Th2 response is desired. In view of the ability of compounds of theinvention to inhibit the Th2 immune response, the compounds are expectedto be useful in the treatment of atopic diseases, e.g., atopicdermatitis, asthma, allergy, allergic rhinitis; systemic lupuserythematosis; as a vaccine adjuvant for cell mediated immunity; andpossibly as a treatment for recurrent fungal diseases and chlamydia.

The immune response modifying effects of the compounds make them usefulin the treatment of a wide variety of conditions. Because of theirability to induce the production of cytokines such as IFN-α and/orTNF-α, the compounds are particularly useful in the treatment of viraldiseases and tumors. This immunomodulating activity suggests thatcompounds of the invention are useful in treating diseases such as, butnot limited to, viral diseases including genital warts; common warts;plantar warts; Hepatitis B; Hepatitis C; Herpes Simplex Virus Type I andType II; molluscum contagiosum; variola, particularly variola major;HIV; CMV; VZV; rhinovirus; adenovirus; influenza; and para-influenza;intraepithelial neoplasias such as cervical intraepithelial neoplasia;human papillomavirus (HPV) and associated neoplasias; fungal diseases,e.g. candida, aspergillus, and cryptococcal meningitis; neoplasticdiseases, e.g., basal cell carcinoma, hairy cell leukemia, Kaposi'ssarcoma, renal cell carcinoma, squamous cell carcinoma, myelogenousleukemia, multiple myeloma, melanoma, non-Hodgkin's lymphoma, cutaneousT-cell lymphoma, and other cancers; parasitic diseases, e.g.pneumocystis carnii, cryptosporidiosis, histoplasmosis, toxoplasmosis,trypanosome infection, and leishmaniasis; and bacterial infections,e.g., tuberculosis, and mycobacterium avium. Additional diseases orconditions that can be treated using the compounds of the inventioninclude actinic keratosis; eczema; eosinophilia; essentialthrombocythaemia; leprosy; multiple sclerosis; Ommen's syndrome; discoidlupus; Bowen's disease; Bowenoid papulosis; alopecia areata; theinhibition of Keloid formation after surgery and other types ofpost-surgical scars. In addition, these compounds could enhance orstimulate the healing of wounds, including chronic wounds. The compoundsmay be useful for treating the opportunistic infections and tumors thatoccur after suppression of cell mediated immunity in, for example,transplant patients, cancer patients and HIV patients.

An amount of a compound effective to induce cytokine biosynthesis is anamount sufficient to cause one or more cell types, such as monocytes,macrophages, dendritic cells and B-cells to produce an amount of one ormore cytokines such as, for example, IFN-α, TNF-α, IL-1, IL-6, IL-10 andIL-12 that is increased over the background level of such cytokines. Theprecise amount will vary according to factors known in the art but isexpected to be a dose of about 100 ng/kg to about 50 mg/kg, preferablyabout 10 μg/kg to about 5 mg/kg. The invention also provides a method oftreating a viral infection in an animal and a method of treating aneoplastic disease in an animal comprising administering an effectiveamount of a compound or composition of the invention to the animal. Anamount effective to treat or inhibit a viral infection is an amount thatwill cause a reduction in one or more of the manifestations of viralinfection, such as viral lesions, viral load, rate of virus production,and mortality as compared to untreated control animals. The preciseamount will vary according to factors known in the art but is expectedto be a dose of about 100 ng/kg to about 50 mg/kg, preferably about 10μg/kg to about 5 mg/kg. An amount of a compound effective to treat aneoplastic condition is an amount that will cause a reduction in tumorsize or in the number of tumor foci. Again, the precise amount will varyaccording to factors known in the art but is expected to be a dose ofabout 100 ng/kg to about 50 mg/kg, preferably about 10 μg/kg to about 5mg/kg.

The invention is further described by the following examples, which areprovided for illustration only and are not intended to be limiting inany way.

In the examples below some of the compounds were purified usingsemi-preparative HPLC. A Waters Fraction Lynx automated purificationsystem was used. The semi-prep HPLC fractions were analyzed using aMicromass LC-TOFMS and the appropriate fractions were combined andcentrifuge evaporated to provide the trifluoroacetate salt of thedesired compound. The structures were confirmed by ¹H NMR.

Column: Phenomenex Luna C18(2), 10×50 mm, 5 micron particle size, 100 Åpore; flow rate: 25 mL/min.; gradient elution from 5-65% B in 4 min.,then 65 to 95% B in 0.1 min, then hold at 95% B for 0.4 min., whereA=0.05 % trifluoroacetic acid/water and B=0.05% trifluoroaceticacid/acetonitrile; fraction collection by mass-selective triggering.

EXAMPLE 1N-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N′-phenylurea

Part A

A solution of 2-(2-aminoethoxy)ethanol (29.0 g, 0.276 mol) in 180 mL oftetrahydrofuran (THF), under N₂, was cooled to 0° C. and treated with140 mL of 2N NaOH solution. A solution of di-tert-butyl dicarbonate(60.2 g, 0.276 mol) in 180 mL of THF was then added dropwise over 1 h tothe rapidly stirred solution. The reaction mixture was then allowed towarm to room temperature and was stirred an additional 18 h. The THF wasthen removed under reduced pressure and the remaining aqueous slurry wasbrought to pH 3 by addition of 150 mL of 1M H₂SO₄ solution. This wasthen extracted with ethyl acetate (300 mL, 100 mL) and the combinedorganic layers were washed with H₂O (2×) and brine. The organic portionwas dried over Na₂SO₄ and concentrated to give tert-butyl2-(2-hydroxyethoxy)ethylcarbamate as a colorless oil (47.1 g).

Part B

A rapidly stirred solution of tert-butyl2-(2-hydroxyethoxy)ethylcarbamate (47.1 g, 0.230 mol) in 1 L ofanhydrous CH₂Cl₂ was cooled to 0° C. under N₂ and treated withtriethylamine (48.0 mL, 0.345 mol). Methanesulfonyl chloride (19.6 mL,0.253 mol) was then added dropwise over 30 min. The reaction mixture wasthen allowed to warm to room temperature and was stirred an additional22 h. The reaction was quenched by addition of 500 mL saturated NaHCO₃solution and the organic layer was separated. The organic phase was thenwashed with H₂O (3×500 mL) and brine. The organic portion was dried overNa₂SO₄ and concentrated to give2-{2-[(tert-butoxycarbonyl)amino]ethoxy}ethyl methanesulfonate as abrown oil (63.5 g).

Part C

A stirred solution of 2-{2-[(tert-butoxycarbonyl)amino]ethoxy}ethylmethanesulfonate (63.5 g, 0.224 mol) in 400 mL of N,N-dimethylformamide(DMF) was treated with NaN₃ (16.1 g, 0.247 mol) and the reaction mixturewas heated to 90° C. under N₂. After 5 h, the solution was cooled toroom temperature and treated with 500 mL of cold H₂O. The reactionmixture was then extracted with Et₂O (3×300 mL). The combined organicextracts were washed with H₂O (4×100 mL) and brine (2×100 mL). Theorganic portion was dried over MgSO₄ and concentrated to give 52.0 g oftert-butyl 2-(2-azidoethoxy)ethylcarbamate as a light brown oil.

Part D

A solution of tert-butyl 2-(2-azidoethoxy)ethylcarbamate (47.0 g, 0.204mol) in MeOH was treated with 4 g of 10% Pd on carbon and shaken underH₂ (3 Kg/cm²) for 24 h. The solution was then filtered through a Celitepad and concentrated to give 35.3 g of crude tert-butyl2-(2-aminoethoxy)ethylcarbamate as a colorless liquid that was usedwithout further purification.

Part E

A stirred solution of 4-chloro-3-nitroquinoline (31.4 g, 0.151 mol) in500 mL of anhydrous CH₂Cl₂, under N₂, was treated with triethylamine (43mL, 0.308 mol) and tert-butyl 2-(2-aminoethoxy)ethylcarbamate (0.151mol). After stirring overnight, the reaction mixture was washed with H₂O(2×300 mL) and brine (300 mL). The organic portion was dried over Na₂SO₄and concentrated to give a bright yellow solid. Recrystallization fromethyl acetate/hexanes gave 43.6 g of tert-butyl2-{2-[(3-nitroquinolin-4-yl)amino]ethoxy}ethylcarbamate as bright yellowcrystals.

Part F

A solution of tert-butyl2-{2-[(3-nitroquinolin-4-yl)amino]ethoxy}ethylcarbamate (7.52 g, 20.0mmol) in toluene was treated with 1.5 g of 5% Pt on carbon and shakenunder H₂ (3 Kg/cm²) for 24 h. The solution was then filtered through aCelite pad and concentrated to give 6.92 g of crude tert-butyl2-{2-[(3-aminoquinolin-4-yl)amino]ethoxy}ethylcarbamate as a yellowsyrup.

Part G

A solution of tert-butyl2-{2-[(3-aminoquinolin4-yl)amino]ethoxy}ethylcarbamate (10.2 g, 29.5mmol) in 250 mL of anhydrous CH₂Cl₂ was cooled to 0° C. and treated withtriethylamine (4.18 mL, 30.0 mmol). Methoxypropionyl chloride (3.30 mL,30.3 mmol) was then added dropwise over 5 min. The reaction was thenwarmed to room temperature and stirring was continued for 1 h. Thereaction mixture was then concentrated under reduced pressure to give anorange solid. This was dissolved in 250 mL of EtOH and 12.5 mL oftriethylamine was added. The mixture was heated to reflux and stirredunder N₂ overnight. The reaction was then concentrated to dryness underreduced pressure and treated with 300 mL of Et₂O. The mixture was thenfiltered and the filtrate was concentrated under reduced pressure togive a brown solid. The solid was dissolved in 200 mL of hot MeOH andtreated with activated charcoal. The hot solution was filtered andconcentrated to give 11.1 g of tert-butyl2-{2-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethylcarbamateas a yellow syrup.

Part H

A solution of tert-butyl2-{2-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethylcarbamate(10.22 g, 24.7 mmol) in 250 mL of CHCl₃ was treated with3-chloroperoxybenzoic acid (MCPBA, 77%, 9.12 g, 40.8 mmol). Afterstirring 30 min, the reaction mixture was washed with 1% Na₂CO₃ solution(2×75 mL) and brine. The organic layer was then dried over Na₂SO₄ andconcentrated to give 10.6 g of tert-butyl2-{2-[2-(2-methoxyethyl)-5-oxido-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethylcarbamateas an orange foam that was used without further purification.

Part I

A solution of tert-butyl2-{2-[2-(2-methoxyethyl)-5-oxido-1H-imidazo[4,5-c]quinolin-l-yl]ethoxy}ethylcarbamate(10.6 g, 24.6 mmol) in 100 mL of 1,2-dichloroethane was heated to 60° C.and treated with 10 mL of concentrated NH₄OH solution. To the rapidlystirred solution was added solid p-toluenesulfonyl chloride (7.05 g,37.0 mmol) over a 10 min period. The reaction mixture was treated withan additional I mL concentrated NH₄OH solution and then sealed in apressure vessel and heating was continued for 2 h. The reaction mixturewas then cooled and treated with 100 mL of CHCl₃. The reaction mixturewas then washed with H₂O, 1% Na₂CO₃ solution (2×) and brine. The organicportion was dried over Na₂SO₄ and concentrated to give 10.6 g oftert-butyl2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethylcarbamateas a brown foam.

Part J

Tert-butyl2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethylcarbamate(10.6 g, 24.6 mmol) was treated with 75 mL of 2M HCl in EtOH and themixture was heated to reflux with stirring. After 1.5 h, the reactionmixture was cooled and filtered to give a gummy solid. The solid waswashed EtOH and Et₂O and dried under vacuum to give the hydrochloridesalt as a light brown solid. The free base was made by dissolving thehydrochloride salt in 50 mL of H₂O and treating with 10% NaOH solution.The aqueous suspension was then concentrated to dryness and the residuewas treated with CHCl₃. The resulting salts were removed by filtrationand the filtrate was concentrated to give 3.82 g of1-[2-(2-aminoethoxy)ethyl]-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amineas a tan powder.

MS 330 (M+H)⁺;

¹H NMR (300 MHz, DMSO-d₆) δ 8.10 (d, J=8.1 Hz, 1H); 7.66 (d, J=8.2 Hz,1H); 7.40 (m, 1H); 7.25 (m, 1H); 6.88 (br s, 2H); 4.78 (t, J=5.4 Hz,2H); 3.89 (t, J=4.8 Hz, 2H); 3.84 (t, J=6.9 Hz, 2H); 3.54 (t, J=5.4 Hz,2H); 3.31 (s, 3H);.3.23 (t, J=6.6 Hz, 2H); 2.88 (t, J=5.3 Hz, 2H).

Part K

1-[2-(2-Aminoethoxy)ethyl]-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amine(750 mg, 2.28 mmol) was dissolved in 30 mL of anhydrous CH₂Cl₂ andcooled to 0° C. under N₂. The reaction mixture was then treated withphenyl isocyanate (247 μL, 2.28 mmol) and Et₃N (0.64 mL, 4.56 mmol) andallowed to warm slowly to room temperature. After stirring for 2 h, thereaction mixture was concentrated under reduced pressure to yield ayellow solid. The yellow solid was dissolved in a minimum amount ofCH₂Cl₂ and EtOAc was added until the solution became turbid. The mixturewas placed in a freezer overnight and white crystal formed. The crystalswere isolated by filtration and were dried under vacuum to give 126 mgofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N′-phenylurea.mp 171.0-174.0° C.;

MS 449 (M+H)⁺;

¹H NMR (300 MHz, DMSO-d₆) δ 8.50 (s, 1H); 8.05 (d, J=7.7 Hz, 1H); 7.62(d, J=8.8 Hz, 1H); 7.44-7.18 (m, 3H); 7.27-7.18 (m, 3H); 6.88 (t, J=7.3Hz, 1H); 6.54 (s, 2H); 6.12 (t, J=5.5 Hz, 2H); 4.76 (t, J=4.8 Hz, 2H);3.88 (t, J=5.3 Hz, 2H); 3.81 (t, J=6.7 Hz, 2H); 3.40 (t, J=6.0 Hz, 2H);3.28 (s, 3H); 3.25-3.14 (m, 4H);

¹³C (75 MHz, DMSO-d₆) δ 155.5, 152.0, 144.9, 140.9, 132.7, 129.0, 126.8,126.5, 121.5, 121.4, 120.5, 117.9, 115.1, 70.5, 69.4, 58.4, 45.5, 27.6;

Anal. Calcd for C₂₄H₂₈N₆O₃.0.21 H₂O: % C, 63.73, % H, 6.33, % N, 18.58.Found: % C, 63.33, % H, 6.28, % N, 18.67.

EXAMPLE 2N-(2-{2-[4-amino-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N′-phenylurea

Part A

1-[2-(2-Aminoethoxy)ethyl]-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amine(10.0 g, 27.3 mmol) was dissolved in 50 mL of trifluoroacetic acid andtreated with PtO₂ (1.0 g). The reaction mixture was shaken under H₂ (3Kg/cm²). After 4 d, an additional 0.5 g of PtO₂ was added andhydrogenation was continued for an additional 3 d. The reaction was thenfiltered through Celite and concentrated under reduced pressure to givea brown oil. The oil was dissolved in 200 mL of H₂O then made basic(pH˜11) by addition of 10% NaOH solution. This was then extracted withCHCl₃ (5×75 mL) and the combined organic layers were dried over Na₂SO₄and concentrated to give 5.17 g of1-[2-(2-aminoethoxy)ethyl]-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amineas a tan solid.

MS 334 (M+H)⁺;

¹H NMR (300 MHz, CDCl₃) δ 5.19 (s, 2H); 4.49.(t, J=5.4 Hz, 2H); 3.84 (t,J=6.6 Hz, 2H); 3.71 (t, J=5.4 Hz, 2H), 3.36 (t, J=5.2 Hz, 2H); 3.51 (s,3H); 3.15 (t, J=6.6 Hz, 2H); 2.95 (m, 2H); 2.82 (m, 2H); 2.76 (t, J=5.1Hz, 2H); 1.84 (m, 4H), 1.47 (brs, 2H).

Part B

1-[2-(2-Aminoethoxy)ethyl]-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine(919 mg, 2.76 mmol) was dissolved in 30 mL of anhydrous CH₂Cl₂ andcooled to 0° C. under N₂. The reaction mixture was then treated withphenyl isocyanate (300 μL, 2.76 mmol) and Et₃N (0.77 mL, 5.51 mmol) andallowed to warm slowly to room temperature. After stirring overnight,the reaction mixture was then quenched by addition of saturated NaHCO₃solution (30 mL). The organic layer was separated and washed with H₂Oand brine, dried over Na₂SO₄ and concentrated under reduced pressure togive a yellow solid. The solid was triturated with Et₂O (30 mL) and afew drops of MeOH. The solid was isolated by filtration and dried undervacuum to give 460 mg ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy)ethyl)-N′-phenylureaas a white powder. m.p. 180-182° C.;

MS 453 (M+H)⁺; ¹H NMR (300 MHz, DMSO-d₆) δ 8.51 (s, 1H); 7.37 (d, J=7.7Hz, 2H); 7.19 (t, J=8.2 Hz, 2H); 6.86 (t, J=7.7 Hz, 1H); 6.11 (t, J=5.5Hz, 2H); 5.70 (s,2H); 4.43 (t, J=5.1 Hz, 2H); 3.78-3.69 (m, 4H); 3.39(t, J=5.6 Hz, 2H); 3.25 (s, 3H); 3.19 (m, 2H); 3.10 (t, J=6.8 Hz, 2H);2.91 (m, 2H); 2.64 (m, 2H); 1.72 (m, 4H);

¹³C (75 MHz, DMSO-d₆) δ 155.5, 151.3, 149.3, 146.3, 140.8, 138.5, 129.0,125.0, 121.4, 118.0, 105.6, 70.6, 70.5, 70.4, 58.4, 44.6, 39.2, 32.7,27.6, 23.8, 23.1, 23.0; Anal. Calcd for C₂₄H₃₂N₆O₃: % C, 63.70, % H,7.13, % N, 18.57. Found: % C, 63.33, % H, 7.16, % N, 18.66.

EXAMPLE 3N-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylurea

Part A

Sodium hydride (60% oil dispersion, 9.1 g, 228 mmol) was placed in around bottom flask and washed with hexanes (3×) under N₂. The driedsodium hydride was treated with 800 mL of anhydrous ThF. A solution oftert-butyl 2-(2-azidoethoxy)ethylcarbamate (41.9 g, 182 mmol) in 200 mLof THF was then added to the stirred sodium hydride solution over 40min. After addition was complete, the reaction was stirred an additional20 min followed by addition of methyl iodide (13.6 mL, 218 mmol). Afterstirring overnight, the reaction was quenched with 300 mL of saturatedNaHCO₃ solution. The reaction mixture was then treated with 200 mL ofH₂O and 1 L of Et₂O. The organic phase was separated and washed with H₂Oand brine. The organic portion was then dried over MgSO₄ andconcentrated under reduced pressure to give 41.9 g of tert-butyl2-(2-azidoethoxy)ethyl(methyl)carbamate as a yellow liquid.

Part B

A solution tert-butyl 2-(2-azidoethoxy)ethyl(methyl)carbamate (41.9 g,170 mmol) in 600 mL of MeOH was treated with 2.5 g of 10% Pd on carbonand shaken under H₂ (3 Kg/cm²) for 24 h. The solution was then filteredthrough a Celite pad and concentrated to give 37.2 g of crude tert-butyl2-(2-aminoethoxy)ethyl(methyl)carbamate as a light yellow liquid.

Part C

A stirred solution of 4-chloro-3-nitroquinoline (32.3 g, 155 mmol) in400 mL of anhydrous CH₂Cl₂, under N₂, was treated with triethylamine(43.1 mL, 310 mmol) and tert-butyl2-(2-aminoethoxy)ethyl(methyl)carbamate (37.2 g, 171 mmol). Afterstirring overnight, the reaction mixture was washed with H₂O (2×300 mL)and brine (300 mL). The organic portion was dried over Na₂SO₄ andconcentrated to give a brown oil. Column chromatography (SiO₂, 33% ethylacetate/hexanes-67% ethyl acetate/hexanes) gave 46.7 g of tert-butylmethyl(2-{2-[(3-nitroquinolin-4-yl)amino]ethoxy}ethyl)carbamate as ayellow solid.

Part D

A solution of tert-butylmethyl(2-{2-[(3-nitroquinolin-4-yl)amino]ethoxy}ethyl)carbamate (6.56 g,16.8 mmol) in 75 mL of toluene was treated with 0.5 g of 5% Pt on carbonand shaken under H₂ (3 Kg/cm²) for 24 h. The solution was then filteredthrough a Celite pad and concentrated to give 6.8 g of crude tert-butyl2-{2-[(3-aminoquinolin-4-yl)amino]ethoxy}ethyl(methyl)carbamate as anorange syrup which was carried on without further purification.

Part E

A solution of tert-butyl2-{2-[(3-aminoquinolin-4-yl)amino]ethoxy}ethyl(methyl)carbamate (6.05 g,16.8 mmol) in 200 mL of anhydrous CH₂Cl₂ was cooled to 0° C. and treatedwith triethylamine (2.40 mL, 17.2 mmol). Methoxypropionyl chloride (1.72mL, 17.2 mmol) was then added dropwise over 5 min. The reaction was thenwarmed to room temperature and stirring was continued for 3 h. Thereaction mixture was then concentrated under reduced pressure to give anorange solid. This was dissolved in 200 mL of EtOH and 7.2 mL oftriethylamine was added. The mixture was heated to reflux and stirredunder N₂ overnight The reaction was then concentrated to dryness underreduced pressure and treated with 300 mL of Et₂O. The mixture was thenfiltered and the filtrate was concentrated under reduced pressure togive a brown solid. This was dissolved in 300 mL of CH₂Cl₂ and washedwith H₂O and brine. The organic portion was dried over Na₂SO₄ andconcentrated under reduced pressure to give a brown oil. The oil wasdissolved in 100 mL of hot MeOH and treated with activated charcoal. Thehot solution was filtered and concentrated to give 7.20 g of tert-butyl2-{2-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamateas a yellow syrup.

Part F

A solution of tert-butyl2-{2-[2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamate(7.20 g, 16.8 mmol) in 200 mL of CH₂Cl₂ was treated with MCPBA (77%,4.32 g, 19.3 mmol). After stirring 6 h, the reaction mixture was treatedwith saturated NaHCO₃ solution and the layers were separated. Theorganic portion was washed with H₂O and brine then dried over Na₂SO₄ andconcentrated to give 7.05 g of tert-butyl2-{2-[2-(2-methoxyethyl)-5-oxido-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamateas a light brown solid.

Part G

A solution of tert-butyl2-{2-[2-(2-methoxyethyl)-5-oxido-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamate(7.05 g, 15.9 mmol) in 100 mL of 1,2-dichloroethane was heated to 80° C.and treated with 5 mL of concentrated NH₄OH solution. To the rapidlystirred solution was added solid p-toluenesulfonyl chloride (3.33 g,17.5 mmol) over a 10 min period. The reaction mixture was treated withan additional 5 mL concentrated NH4OH solution and then sealed in apressure vessel and heating was continued for 4 h. The reaction mixturewas then cooled and treated with 100 mL of CH₂Cl₂. The reaction mixturewas then washed with H₂O, 1% Na₂CO₃ solution (3×) and brine. The organicportion was dried over Na₂SO₄ and concentrated to give 6.50 g oftert-butyl2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamateas a brown oil.

Part H

Tert-butyl2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl(methyl)carbamate(6.50 g, 14.7 mmol) was dissolved in 100 mL of EtOH and treated with 20mL of 2M HCl in EtOH and the mixture was heated to reflux with stirring.After 6 h, the reaction mixture was cooled and filtered to give a gummysolid. The solid was washed with EtOH and Et₂O and dried under vacuum togive the hydrochloride salt as a light brown powder. The free base wasmade by dissolving the hydrochloride salt in 50 mL of H₂O and treatingwith 5 mL of concentrated NH₄OH. The aqueous suspension was extractedwith CH₂Cl₂ (5×50 mL). The combined organic layers were dried overNa₂SO₄ and concentrated to give 3.93 g of2-(2-methoxyethyl)-1-{2-[2-(methylamino)ethoxy]ethyl}-1H-imidazo[4,5-c]quinolin-4-amineas a tan powder.

MS 344 (M+H)⁺;

¹H NMR (300 MHz, DMSO-d₆) δ 8.07 (d, J=7.7 Hz, 1H); 7.62 (dd, J=1.0, 8.3Hz, 1H); 7.42 (ddd, J=1.0, 7.1, 8.2 Hz, 1H); 7.22 (ddd, J=1.1, 7.1, 8.2Hz, 1H); 6.49 (s, 2H); 4.75 (t, J=5.1 Hz, 2H); 3.83 (t, J=6.8 Hz, 4H);3.35 (t, J=5.6 Hz, 2H); 3.30 (s, 3H); 3.21 (t, J=6.9 Hz, 2H); 2.45 (t,J=5.6 Hz, 2H); 2.12 (s, 3H).

Part I

2-(2-Methoxyethyl)-1-{2-[2-(methylamino)ethoxy]ethyl}-1H-imidazo[4,5c]quinolin-4-amine(929 mg, 2.71 mmol) was dissolved in 30 mL of anhydrous CH₂Cl₂ andtreated with phenyl isocyanate (300 μL, 2.76 mmol). After stirring underN₂ overnight, the reaction mixture was concentrated under reducedpressure. Purification by column chromatography (SiO₂, 3% MeOH/CHCl₃saturated with aqueous NH₄OH) gave the product as a white solid.Crystallization from H₂O and MeOH gave 610 mg ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylureaas a flakey white crystals. m.p. 184.8-185.8° C.;

MS 463 (M+H)⁺;

¹H NMR (300 MHz, DMSO-d₆) δ 8.16 (s, 1H); 8.06 (d, J=7.7 Hz, 1H); 7.61(dd, J=1.0, 8.3 Hz, 1H); 7.43-7.38 (m, 3H); 7.25-7.17 (m, 3H); 6.91 (t,J=7.3 Hz, 1H); 6.47 (s, 2H); 4.76 (t, J=5.0 Hz, 2H); 3.88 (t, J=5.1 Hz,2H); 3.78 (t, J=6.8 Hz, 2H); 3.48 (t, J=5.2 Hz, 2H); 3.39 (t, J=5.4 Hz,2H); 3.27 (s, 3H); 3.20 (t, J=6.8 Hz, 2H); 2.82 (s,3H);

¹³C NMR (75 MHz, DMSO-d₆) δ 155.6, 152.0, 151.9, 145.1, 140.9, 132.7,128.5, 126.7, 126.6, 122.0, 121.4, 120.5, 120.1, 115.1, 70.5, 69.6,69.4, 58.4, 47.7, 45.5, 35.4, 27.6.

Anal. Calcd for C₂₅H₃₀N₆O₃.0.12H₂O: % C, 64.62; % H, 6.56; % N, 18.08.Found: % C, 64.69; % H, 6.65; % N, 18.09.

EXAMPLE 4N-(2-{2-[4-amino-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylurea

Part A

2-(2-Methoxyethyl)-1-{2-[2-(methylamino)ethoxy]ethyl}-1H-imidazo[4,5-c]quinolin-4-amine(4.22 g, 12.3 mmol) was dissolved in 25 mL of trifluoroacetic acid andtreated with PtO₂ (0.5 g). The reaction mixture was shaken under H₂ (3Kg/cm²). After 4 d, an additional 0.5 g of PtO₂ was added andhydrogenation was continued for an additional 3 d. The reaction was thenfiltered through Celite and concentrated under reduced pressure to givea yellow oil. The yellow oil was dissolved in 50 mL of H₂O and extractedwith 50 mL of CHCl₃. The organic portion was removed and discarded. Theaqueous portion was then made basic (pH˜12) by addition of 10% NaOHsolution. This was then extracted with CHCl₃ (6×50 mL) and the combinedorganic layers were dried over Na₂SO₄ and concentrated to a brown oil.The brown oil was dissolved in 100 mL of hot MeOH and treated with 1 gof activated charcoal. The hot solution was filtered through Celite andconcentrated to dryness. The resulting gummy solid was concentratedseveral times with Et₂O to give 3.19 g of2-(2-methoxyethyl)-1-{2-[2-(methylamino)ethoxy]ethyl}-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amineas an off-white powder.

MS 348 (M+H)⁺;

¹H NMR (300 MHz, CDCl₃) δ 4.84 (s, 2H); 4.48 (t, J=5.7 Hz, 2H); 3.84 (t,J=6.7 Hz, 2H); 3.70 (t, J=5.7 Hz, 2H); 3.46 (t, J=5.1 Hz, 2H); 3.36 (s,3H); 3.14 (t, J=6.7 Hz, 2H); 2.96 (m, 2H); 2.83 (m, 2H); 2.65 (t, J=5.1Hz, 2H); 2.36 (s, 3H); 1.85 (m, 4H).

Part B

2-(2-Methoxyethyl)-1-{2-[2-(methylamino)ethoxy]ethyl}-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-4-amine(750 mg, 2.16 mmol) was dissolved in 30 mL of anhydrous CH₂Cl₂ andtreated with phenyl isocyanate (239 μL, 2.20 mmol). After stirring underN₂ overnight, the reaction mixture was concentrated under reducedpressure. Crystallization from EtOAc and CH₂Cl₂ gave 170 mg ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-6,7,8,9-tetrahydro-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylureaas fluffy white crystals. m.p. 167.7-170.0° C.;

MS 467 (M+H)⁺;

¹H NMR (300 MHz, DMSO-d₆) δ 8.17 (s, 1H); 7.43 (d, J=7.6 Hz, 2H); 7.21(t, J=7.9 Hz, 2H); 6.91 (t, J=7.3 Hz, 1H); 5.65 (s, 2H); 4.43 (t, J=5.0Hz, 2H); 3.72 (t, J=7.0 Hz, 2H); 3.70 (t, J=5.2 Hz, 2H); 3.46-3.41 (m,4H); 3.24 (s, 3H); 3.07 (t, J=6.9 Hz, 2H); 2.92 (m, 2H); 2.85 (s, 3H);2.64 (m, 2H); 1.72 (m, 4H);

¹³C NMR (75 MHz, DMSO-d₆) δ 155.6, 151.2, 149.3, 146.3, 140.9, 138.4,128.5, 124.9, 122.0, 120.1, 105.5, 70.7, 70.5, 69.5, 58.4, 48.0, 44.6,35.5, 32.8, 27.6, 23.8, 23.1, 23.0.

Anal. Calcd for C₂₅H₃₄N₆O₃: % C, 64.36; % H, 7.35; % N, 18.01. Found: %C, 64.04; % H, 7.38; % N, 18.02.

EXAMPLE 5N-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)morpholine-4-carboxamide

Under a nitrogen atmosphere,1-[2-(2-aminoethoxy)ethyl]-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-4-amine(0.75 g, 2.3 mmol) was dissolved in dichloromethane (30 mL) andtriethylamine (0.64 mL, 4.6 mmol) using mild heat and vigorous stirring.The solution was chilled in an ice-water bath and 4-morpholinecarbonylchloride (0.27 mL, 2.3 mmol) was added dropwise. The cooling bath wasremoved and the reaction was stirred for an additional 4 hours. Thereaction was quenched by the addition of saturated sodium bicarbonatesolution (25 mL). The phases were separated and the organic layer waswashed with water (3×25 ml), brine (25 mL), dried (Na₂SO₄), filtered andconcentrated to yield a yellow foam. The product was recrystallized fromdichloromethane and ethyl acetate. The crystals were triturated withether (2×5 mL) to remove residual solvent. The final product was driedin a vacuum oven to provide 200 mg ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)morpholine-4-carboxamideas a tan crystalline solid, m.p. 164-166° C.

¹H NMR (300 MHz, DMSO-d₆) δ 8.06 (d, J=8.1 Hz, 1H), 7.61 (d, J=7.3 Hz,1H), 7.42 (t, J=7.2 Hz, 1H), 7.23 (t, J=7.8 Hz, 1H), 6.51 (s, 2H), 6.33(t, J=5.0 Hz, 1H), 4.74 (t, J=4.3 Hz, 2H), 3.85-3.81 (m, 4H), 3.49 (t,J=4.3 Hz, 4H), 3.33 (t, J=5.9 Hz, 2H), 3.30 (s, 3H), 3.21 (t, J=6.8 Hz,2H), 3.14 (t, J=4.5 Hz, 4H), 3.08 (t, J=6.0 Hz, 2H);

¹³C NMR (75 MHz, DMSO-d₆) δ 157.8, 151.9, 145.0, 132.7, 126.7, 126.6,121.4, 120.5, 115.1, 70.4, 70.2, 69.2, 58.4, 45.5, 44.0, 27.6;

Anal. Calcd for C₂₂H₃₀N₆O₄: % C, 59.71, % H, 6.83, % N, 18.99. Found: %C, 59.71, % H, 6.80,% N, 18.78;

MS(CI) m/e 443 (M+H)

EXAMPLE 6N-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methylmorpholine-4-carboxamide

2-(2-Methoxyethyl)-1-(2-[2-(methylamino)ethoxy]ethyl}-1H-imidazo[4,5-c]quinolin-4-amine(802 mg, 2.34 mmol) was dissolved in 30 mL of anhydrous CH₂Cl₂ andcooled to 0° C. under N₂. To the stirred solution were added Et₃N (0.65mL, 4.68 mmol) and morpholinecarbonyl chloride (273 μL, 2.34 mmol) andthe reaction was allowed to warm to room temperature overnight. Thereaction mixture was then quenched by addition of saturated NaHCO₃solution (30 mL) and CH₂Cl₂ (30 mL). The organic layer was separated andwashed with H₂O and brine, dried over Na₂SO₄ and concentrated underreduced pressure. Purification by column chromatography (SiO₂, 2-5%MeOH/CHCl₃ saturated with aqueous NH₄OH) gave the product as a colorlessfoam. Crystallization from EtOAc gave 640 mg ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methylmorpholine-4-carboxamideas white crystals. Mp=121.8-122.3° C.

MS 457 (M+H)⁺;

¹H NMR (500 MHz, DMSO-d₆) δ 8.06 (dd, J=0.9, 8.3 Hz, 1H); 7.61 (dd,J=1.1, 8.3 Hz, 1H); 7.41 (ddd, J=1.2, 7.0, 8.3 Hz, 1H); 7.22 (4dd,J=1.3, 7.0, 8.1 Hz, 1H); 6.44 (s, 2H); 4.74 (t, J=5.2 Hz, 2H); 3.84 (t,J=5.2 Hz, 2H); 3.82 (t, J=6.9 Hz, 2H); 3.50-3.43 (m, 6H); 3.30 (s, 3H);3.20 (t, J=6.9 Hz, 2H); 3.16 (t, J=5.5 Hz, 2H); 2.88 (t, J=4.7 Hz, 4H);2.59 (s, 3H);

¹³C NMR (75 MHz, DMSO-d₆) δ 163.8, 152.0, 151.8, 145.2, 132.7, 126.7,121.3, 120.6, 115.1, 70.4, 69.4, 68.9, 66.1, 58.5, 49.1, 47.3, 45.5,36.9, 27.7.

Anal. Calcd for C₂₃H₃₂N₆O₄: % C, 60.51; % H, 7.07; % N, 18.41. Found: %C, 60.56; % H, 6.85; % N, 18.19.

EXAMPLES 7-21

Part A

A solution of tert-butyl2-{2-[(3-aminoquinolin-4-yl)amino]ethoxy}ethylcarbamate (3.46 g, 10.0mmol) in 50 mL of toluene was treated with triethylorthovalerate (2.5mL, 14.5 mmol) and the reaction mixture was heated to reflux. A 25 mgportion of pyridinium hydrochloride was then added and refluxing wascontinued for 4 h. The reaction was then concentrated to dryness underreduced pressure. The residue was dissolved in 50 mL of CH₂Cl₂ andwashed with saturated NaHCO₃, H₂O and brine. The organic portion wasdried over Na₂SO₄ and concetrated to give a green oil. The green oil wasdissolved in 50 mL of hot MeOH and treated with activated charcoal. Thehot solution was filtered and concentrated to give 4.12 g of tert-butyl2-[2-(2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate as ayellow oil.

Part B

A solution of tert-butyl2-[2-(2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate (4.12g, 10.0 mmol) in 50 mL of CH₂Cl₂ was treated with 3-chloroperoxybenzoicacid (MCPBA, 77%, 2.5 g; 11.2 mmol). After stirring for 5 h, thereaction mixture was treated with saturated NaHCO₃ solution and thelayers were separated. The organic portion was washed with H₂O and brinethen dried over Na₂SO₄ and concentrated to give 3.68 g of tert-butyl2-[2-(2-butyl-5-oxido-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamateas a light brown foam.

Part C

A solution of tert-butyl2-[2-(2-butyl-5-oxido-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate(3.68 g, 8.60 mmol) in 100 mL of 1,2-dichloroethane was heated to 80° C.and treated with 10 mL of concentrated NH₄OH solution. To the rapidlystirred solution was added solid p-toluenesulfonyl chloride (1.87 g,9.81 mmol) over a 10 min period. The reaction mixture was then sealed ina pressure vessel and heating was continued for 2 h. The reactionmixture was then cooled and treated with 100 mL of CH₂Cl₂. The reactionmixture was then washed with H₂O, 1% Na₂CO₃ solution (3×) and brine. Theorganic portion was dried over Na₂SO₄ and concentrated to give 3.68 g oftert-butyl2-[2-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamateas a light brown foam.

Part D

Tert-butyl2-[2-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate(3.68 g, 8.60 mmol) was suspended in 20 mL of 2M HCl in EtOH and themixture was heated to reflux with stirring. After 3 h, the reactionmixture was concentrated to give a solid. The solid was triturated withhot EtOH (50 mL) and filtered to give 2.90 g of the product as thehydrochloride salt. The free base was made by dissolving thehydrochloride salt in 50 mL of H₂O and treating with 5 mL ofconcentrated NH₄OH. The aqueous suspension was extracted with CH₂Cl₂(3×50 mL). The combined organic layers were dried over Na₂SO₄ andconcentrated to give1-[2-(2-aminoethoxy)ethyl]-2-butyl-1H-imidazo[4,5-c]quinolin-4-amine asa tan powder.

MS 328 (M+H)⁺;

¹H NMR (300 MHz, CDCl₃) δ 7.95 (d, J=8.3 Hz, 1H); 7.83 (d, J=8.4 Hz,1H); 7.50 (m, 1H);,7.30 (m, 1H); 5.41 (s, 2H); 4.69 (t, J=5.6 Hz, 2H);3.93 (t, J=5.6 Hz, 2H); 3.39 (t, J=5.1 Hz,2H); 2.97 (t, J=7.9 Hz, 2H);2.76 (t, J=5.1 Hz, 2H); 1.89 (m, 2H); 1.52 (m, 2H); 1:26 (brs, 2H); 1.01(t, J=7.3 Hz, 3H).

Part E

The compounds in the table below were prepared according to thesynthetic method of step (7) of Reaction Scheme I above using thefollowing general method.

The isocyanate (84 μmol.) was added to a test tube containing a solutionof 1-[2-(2-aminoethoxy)ethyl]-2-butyl-1H-imidazo[4,5-c]quinolin-4-amine(25 mg, 76 μmol) in dichloromethane (5 mL). The test tube was capped andthen placed on a shaker at ambient temperature for 20 hr. The solventwas removed by vacuum centrifugation. The residue was purified bysemi-preparative HPLC using the method described above. The table belowshows the structure of the free base and the observed accurate mass(M+H). Example Accurate Mass Number Structure of Free Base (obs.) 7

413.2644 8

427.2841 9

427.2823 10

447.2496 11

441.2638 12

453.2980 13

472.2457 14

477.2611 15

487.2804 16

490.2919 17

493.2386 18

207.2741 19

511.2120 20

525.2280 21

545.1758

EXAMPLES 22-36

Part A

Using the general method of Part A of Examples 7-21, 4-piperidineethanol (10 g, 77.4 mmol) was reacted with di-tert-butyl dicarbonate(17.7 g, 81.3 mmol) to provide 13.1 g of tert-butyl4-(2-hydroxyethyl)piperidine-1-carboxylate as a clear oil.

Part B

Iodine (7.97 g) was added in three portions to a solution of imidazole(3.89 g, 57.1 mmol) and triphenylphosphine (14.98 g, 57.1 mmol) indichloromethane (350 mL). After 5 minutes a solution of the materialfrom Part A in dichloromethane (70 mL) was added. The reaction mixturewas stirred at ambient temperature overnight. More iodine (7.97 g) wasadded and the reaction was stirred at ambient temperature for 1 hr. Thereaction mixture was washed with saturated sodium thiosulfate (2×) andbrine, dried over sodium sulfate, filtered and then concentrated underreduced pressure to provide an oily residue. The residue was purified bycolumn chromatography (silica gel eluting with 20% ethyl acetate inhexanes) to provide 15.52 g of tert-butyl4-(2-iodoethyl)piperidine-1-carboxylate as a pale yellow oil.

Part C

Under a nitrogen atmosphere,2-(1H-imidazo[4,5-c]quinolin-1-yl)butan-1-ol (6.5 g, 26.9 mmol) wasadded in three portions to a suspension of sodium hydride (1.4 g of 60%,35.0 mmol) in anhydrous N,N-dimethylformamide. The reaction mixture wasallowed to stir for 45 minutes by which time gas evolution had ceased.Tert-butyl 4-(2-iodoethyl)piperidine-1-carboxylate (10.05 g, 29.6 mmol)was added dropwise over a period of 15 minutes. The reaction mixture wasallowed to stir at ambient temperature for 2.5 hrs; then it was heatedto 100° C. and stirred overnight. Analysis by HPLC showed that thereaction was about 35% complete. Saturated ammonium chloride solutionwas added, the resulting mixture was allowed to stir for 20 minutes andthen it was extracted with ethyl acetate (2×). The ethyl acetateextracts were washed with water (2×) and then with brine, combined,dried over sodium sulfate, filtered and then concentrated under reducedpressure to provide a brown oil. The oil was purified by columnchromatography (silica gel eluting sequentially with 30% ethyl acetatein hexanes, 50% ethyl acetate in hexanes, and ethyl acetate) to provide2.2 g of tert-butyl4-{2-[2-(1H-imidazo[4,5-c]quinolin-1-yl)butoxy]ethyl}piperidine-1-carboxylate.

Part D

Using the general method of Examples 7-21 Part H, the material from PartC was oxidized to provide tert-butyl4-{2-[2-(5-oxido-1H-imidazo[4,5-c]quinolin-1-yl)butoxy]ethyl}piperidine-1-carboxylateas an oil.

Part E

Ammonium hydroxide solution (20 mL) was added to, a solution of thematerial from Part D in dichloromethane (20 mL). A solution of tosylchloride (0.99 g, 5.2 mmol) in dichloromethane (10 mL) was added over aperiod of 5 minutes. The resulting biphasic reaction mixture was allowedto stir overnight. The reaction mixture was diluted with chloroform andsaturated sodium bicarbonate solution. The layers were separated. Theorganic layer was dried over sodium sulfate, filtered and thenconcentrated under reduced pressure to provide a brown glass. Thismaterial was purified by column chromatography (silica gel eluting firstwith 50% ethyl acetate in hexanes and then with ethyl acetate) toprovide 1.0 g of tert-butyl4-{2-[2-(4-amino-1H-imidazo[4,5-c]quinolin-1-yl)butoxy]ethyl}piperidine-1-carboxylateas pale yellow glassy foam.

Part F

Under a nitrogen atmosphere, tert-butyl 4-{2-[2-(4-amino-1H-imidazo[4,5-c]quinolin-1-yl)butoxy]ethyl}piperidine-1-carboxylate(1.00 g, 2.1 mmol) and 2N ethanolic hydrochloric acid (10 ml, 20 mmol)were combined and the solution was stirred at ambient temperature for 14hours. The solvent was removed in vacuo and the resulting tan solid wasdissolved in water. Saturated aqueous sodium carbonate was added untilthe pH reached 10. After extraction with dichloromethane (3×), theorganic fractions were combined, washed with brine, dried (Na₂SO₄),filtered, and the majority of the solvent was removed in vacuo. Hexanewas added to form a precipitate. Vacuum filtration yielded 0.5 g of1-{1-[(2-piperidin-4-ylethoxy)methyl]propyl}-1H-imidazo[4,5-c]quinolin-4-amineas a tan powder.

¹H-NMR (300MHz, DMSO-d₆): δ 8.34 (bs, 1H), 8.19 (d, J=8.49 Hz, 1H), 7.61(dd, J=8.31, 1.13 Hz, 1H), 7.45-7.39 (m, 1H), 7.25-7.19 (m, 1H), 6.55(s, 2H), 5.25-5.15 (m, 1H), 4.00-3.80 (m, 2H), 3.5-3.3 (m, 2H), 2.8-2.64(m, 2H), 2.22-2.11 (m, 2H), 2.09-1.99 (m, 2H), 1.8-1.63 (bs, 1H),1.37-1.0 (m, 5H), 0.95-0.7 (m, 5H);

¹³C-NMR (75 MHz, DMSO-d₆): δ 152.8, 145.8, 140.6, 133.0, 127.8, 127.0,126.9, 121.3, 121.0, 115.5, 71.8, 68.1, 58.4, 46.1, 36.3, 33.1, 32.7,24.5, 9.9;

MS (CI) m/e 368.2459 (368.2450 calcd for C₂₁H₃₀N₅O).

Part G

The compounds in the table below were prepared according to thesynthetic method of step (7) of Reaction Scheme I above using thefollowing general method.

The isocyanate or isothiocyanate (75 μmol.) was added to a test tubecontaining a solution of1-{1-[(2-piperidin-4-ylethoxy)methyl]propyl}-1H-imidazo[4,5-c]quinolin-4-amine(25 mg, 68 μmol) in dichloromethane (5 mL). The test tube was capped andthen placed on a shaker at ambient temperature for 20 hr. The solventwas removed by vacuum centrifugation. The residue was purified bysemi-preparative HPLC using the method described above. The table belowshows the structure of the free base and the observed accurate mass(M+H). Example Accurate Mass Number Stucture of Free Base (obs.) 22

453.2983 23

467.3138 24

487.2787 25

481.2930 26

493.3270 27

512.2757 28

517.2907 29

527.3112 30

529.2911 31

533.2704 32

547.3032 33

565.2641 34

585.2056 35

521.2297 36

503.2589

EXAMPLES 37-44

Part A

A solution of tert-butyl2-{2-[(3-aminoquinolin-4-yl)amino]ethoxy}ethylcarbamate (6.92 g, 20.0mmol) in 100 mL of toluene was treated with triethylorthoformate (4.65mL, 28.0 mmol) and the reaction mixture was heated to reflux. A 100 mgportion of pyridinium hydrochloride was then added and refluxing wascontinued for 2 h. The reaction was then concentrated to dryness underreduced pressure. The residue was dissolved in 200 mL of CH₂Cl₂ andwashed with saturated NaHCO₃, H₂O and brine. The organic portion wasdried over Na₂SO₄ and concentrated to give a green oil. The green oilwas dissolved in 200 mL of hot MeOH and treated with 10 g of activatedcharcoal. The hot solution was filtered and concentrated to give 5.25 gof tert-butyl 2-[2-(1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamateas a light yellow syrup.

Part B

A solution of tert-butyl2-[2-(1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate (5.25 g, 14.7mmol) in 200 mL of CH₂Cl₂ was treated with MCPBA (77%, 3.63 g, 16.3mmol). After stirring overnight, the reaction mixture was treated withsaturated NaHCO₃ solution and the layers were separated. The organicportion was washed with H₂O and brine then dried over Na₂SO₄ andconcentrated to give 4.60 g of tert-butyl2-[2-(5-oxido-1H-imidazo[4,5-c]quinolin-1yl)ethoxy]ethylcarbamate as alight brown foam.

Part C

A solution of tert-butyl2-[2-(5-oxido-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate (4.60g, 12.4 mmol) in 150 mL of 1,2-dichloroethane was heated to 80° C. andtreated with 10 mL of concentrated NH₄OH solution. To the rapidlystirred solution was added solid p-toluenesulfonyl chloride (2.71 g,14.2 mmol) over a 10 min period. The reaction mixture was treated withan additional 2 mL of concentrated NH₄OH solution and then sealed in apressure vessel and heating was continued for 3 h. The reaction mixturewas then cooled and treated with 100 mL of CH₂Cl₂. The reaction mixturewas then washed with H₂O, 1% Na₂CO₃ solution (3×) and brine. The organicportion was dried over Na₂SO₄ and concentrated to give 4.56 g oftert-butyl2-[2-(4-amino-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate as alight brown foam.

Part D

Tert-butyl2-[2-(4-amino-1H-imidazo[4,5-c]quinolin-1-yl)ethoxy]ethylcarbamate (4.56g, 12.3 mmol) was dissolved in 100 mL of EtOH and treated with 30 mL of2M HCl in EtOH and the mixture was heated to reflux with stirring. After3 h, the reaction mixture was concentrated to give a solid. The solidwas triturated with hot EtOH (100 mL) and filtered to give the productas the hydrochloride salt. The free base was made by dissolving thehydrochloride salt in 50 mL of H₂O and treating with 5 mL ofconcentrated NH₄OH. The aqueous suspension was extracted with CH₂Cl₂(5×50 mL). The combined organic layers were dried over Na₂SO₄ andconcentrated to give 1.35 g of1-[2-(2-aminoethoxy)ethyl]-1H-imidazo[4,5-c]quinolin-4-amine as a tanpowder.

MS 272 (M+H)⁺;

¹H NMR (300 MHz, CDCl₃) δ 7.98 (d, J=8.2 Hz, 1H); 7.88 (s, 1H); 7.84 (d,J=8.4 Hz, 1H); 7.54 (m, 1H); 7.32 (m, 1H); 5.43 (s, 2H); 4.74 (t, J=5.2Hz, 2H); 3.97 (t, J=5.2 Hz, 2H); 3.42 (t, J=5.1 Hz, 2H); 2.78 (t, J=5.lHz, 2H); 1.10 (br s, 2H).

Part E

The compounds in the table below were prepared according to thesynthetic method of step (7) of Reaction Scheme I above using thefollowing general method.

1-[2-(2-Aminoethoxy)ethyl]-1H-imidazo[4,5-c]quinolin-4-amine (20 mg, 74μmol) and 1-methyl-2-pyrrolidinone (5 mL) were combined in a test tubeand then sonicated with heating to provide a solution. The isocyanate(81 μmol.) was added, the test tube was capped and then placed on ashaker at ambient temperature for 20 hr. The solvent was removed byvacuum centrifugation. The residue was purified by semi-preparative HPLCusing the method described above. The table below shows the structure ofthe free base and the observed accurate mass (M+H). Example AccurateMass Number Stucture of Free Base (obs.) 37

371.2204 38

391.1884 39

397.2373 40

416.1844 41

421.1946 42

431.2206 43

451.2115 44

455.1513

Cytokine Induction in Human Cells

An in vitro human blood cell system is used to assess cytokineinduction. Activity is based on the measurement of interferon (a) andtumor necrosis factor (α) (IFN and TNF, respectively) secreted intoculture media as described by Testerman et. al. in “Cytokine Inductionby the Immunomodulators Imiquimod and S-27609”, Journal of LeukocyteBiology, 58, 365-372 (September, 1995).

Blood Cell Preparation for Culture

Whole blood from healthy human donors is collected by venipuncture intoEDTA vacutainer tubes. Peripheral blood mononuclear cells (PBMCs) areseparated from whole blood by density gradient centrifugation usingHistopaque®-1077. The PBMCs are washed twice with Hank's Balanced SaltsSolution and then are suspended at 3-4×10⁶ cells/mL in RPMI complete.The PBMC suspension is added to 48 well flat bottom sterile tissueculture plates (Costar, Cambridge, Mass. or Becton Dickinson Labware,Lincoln Park, N.J.) containing an equal volume of RPMI complete mediacontaining test compound.

Compound Preparation

The compounds are solubilized in dimethyl sulfoxide (DMSO). The DMSOconcentration should not exceed a final concentration of 1% for additionto the culture wells.

Incubation

The solution of test compound is added to the first well containing RPMIcomplete and serial dilutions are made in the wells. The PBMC suspensionis then added to the wells in an equal volume, bringing the testcompound concentrations to the desired range The final concentration ofPBMC suspension is 1.5-2×10⁶ cells/mL. The plates are covered withsterile plastic lids, mixed gently and then incubated for 18 to 24 hoursat 37° C. in a 5% carbon dioxide atmosphere.

Separation

Following incubation the plates are centrifuged for 5-10 minutes at 1000rpm (˜200×g) at 4° C. The cell-free culture supernatant is removed witha sterile polypropylene pipet and transferred to sterile polypropylenetubes. Samples are maintained at −30 to −70° C. until analysis. Thesamples are analyzed for interferon (α) and for tumor necrosis factor(α) by ELISA.

Interferon (α) and Tumor Necrosis Factor (α) Analysis by ELISA

Interferon (α) concentration is determined by ELISA using a HumanMulti-Species kit from PBL Biomedical Laboratories, New Brunswick, N.J.Results are expressed in pg/mL.

Tumor necrosis factor (α) concentration is determined using ELISA kitsavailable from Genzyme, Cambridge, Mass.; R&D Systems, Minneapolis,Minn.; or Pharmingen, San Diego, Calif. Results are expressed in pg/mL.

The table below lists the lowest concentration found to induceinterferon and the lowest concentration found to induce tumor necrosisfactor for each compound. A “*” indicates that no induction was seen atany of the tested concentrations; generally the highest concentrationtested was 10 or 30 μM. Cytokine Induction in Human Cells Example LowestEffective Concentration (μM) Number Interferon Tumor Necrosis Factor 30.01 0.37 7 0.0001 10 8 0.0001 10 9 0.0001 1 10 0.0001 10 11 0.0001 0.112 0.0001 1 13 0.0001 1 14 0.0001 10 15 0.0001 0.1 16 0.0001 10 17 * 1018 1 * 19 0.1 10 20 0.01 10 21 1 10 22 0.1 1 23 1 1 24 0.1 1 25 0.1 1 260.1 1 27 0.1 1 28 0.1 1 29 0.1 1 30 1 1 31 1 10 32 0.1 1 33 1 10 34 1 1035 1 1 36 0.1 * 37 10 10 38 10 10 39 10 10 40 10 10 41 10 10 42 10 * 4310 10 44 * *

1-23. (canceled)
 24. A method of inducing cytokine biosynthesis in ananimal comprising administering a compound selected from the groupconsisting ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N′-phenylureaandN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylurea,or a pharmaceutically acceptable salt thereof to the animal in an amounteffective for cytokine induction.
 25. The method of claim 24 wherein thecytokine is IFN-α and/or TNF-α.
 26. A method of treating a viral diseasein an animal in need thereof comprising administering to the animal atherapeutically effective amount of a compound selected from the groupconsisting ofN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N′-phenylureaandN-(2-{2-[4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl]ethoxy}ethyl)-N-methyl-N′-phenylurea,or a pharmaceutically acceptable salt thereof that induces cytokinebiosynthesis.